Many of mine are grammar related (comes from having a mother with a masters in Eng lit, I think) It's when it does not stand for "it is" alot, (that should be TWO words, thanks) and forms of words that are meaningless. For example: irregardless--I can't even get started on that one--and orientated!!!! Oh yeah, that one makes me crazy! What happened to just ORIENTED? They mean the same thing, for pete's sake.
People who say "Oh my God"--gosh will do just as well.
Unwiped runny noses, especially when the poor little one's hair is stuck on there. Ick ick ick.
Minnesota drivers--CLUELESS!
People who bring their children to the grocery store late at night and then get mad at them for being cranky.